#pragma once

#include <string>
#include <map>
#include <iostream>
#include <fstream>
#include <sstream>

namespace rmd
{
class LanConfig {
	// Data
protected:
	std::string m_Delimiter;  //!< separator between key and value
	std::string m_Comment;    //!< separator between value and comments
	std::map<std::string, std::string> m_Contents;  //!< extracted keys and values

	typedef std::map<std::string, std::string>::iterator mapi;
	typedef std::map<std::string, std::string>::const_iterator mapci;
	// Methods
public:

	LanConfig(std::string filename, std::string delimiter = "=", std::string comment = "#");
	LanConfig();
	template<class T> T Read(const std::string& in_key) const;  //!<Search for key and read value or optional default value, call as read<T>
	template<class T> T Read(const std::string& in_key, const T& in_value) const;
	template<class T> bool ReadInto(T& out_var, const std::string& in_key) const;
	template<class T>
	bool ReadInto(T& out_var, const std::string& in_key, const T& in_value) const;
	bool FileExist(std::string filename);
	void ReadFile(std::string filename, std::string delimiter = "=", std::string comment = "#");

	// Check whether key exists in configuration
	bool KeyExists(const std::string& in_key) const;

	// Modify keys and values
	template<class T> void Add(const std::string& in_key, const T& in_value);
	void Remove(const std::string& in_key);

	// Check or change configuration syntax
	std::string GetDelimiter() const { return m_Delimiter; }
	std::string GetComment() const { return m_Comment; }
	std::string SetDelimiter(const std::string& in_s)
	{
		std::string old = m_Delimiter;  m_Delimiter = in_s;  return old;
	}
	std::string SetComment(const std::string& in_s)
	{
		std::string old = m_Comment;  m_Comment = in_s;  return old;
	}

	// Write or read configuration
	friend std::ostream& operator<<(std::ostream& os, const LanConfig& cf);
	friend std::istream& operator>>(std::istream& is, LanConfig& cf);

protected:
	template<class T> static std::string T_as_string(const T& t);
	template<class T> static T string_as_T(const std::string& s);
	static void Trim(std::string& inout_s);


	// Exception types
public:
	struct File_not_found {
		std::string filename;
		File_not_found(const std::string& filename_ = std::string())
			: filename(filename_) {}
	};
	struct Key_not_found {  // thrown only by T read(key) variant of read()
		std::string key;
		Key_not_found(const std::string& key_ = std::string())
			: key(key_) {}
	};
};


/* static */
template<class T>
std::string LanConfig::T_as_string(const T& t)
{
	// Convert from a T to a string
	// Type T must support << operator
	std::ostringstream ost;
	ost << t;
	return ost.str();
}


/* static */
template<class T>
T LanConfig::string_as_T(const std::string& s)
{
	// Convert from a string to a T
	// Type T must support >> operator
	T t;
	std::istringstream ist(s);
	ist >> t;
	return t;
}


/* static */
template<>
inline std::string LanConfig::string_as_T<std::string>(const std::string& s)
{
	// Convert from a string to a string
	// In other words, do nothing
	return s;
}


/* static */
template<>
inline bool LanConfig::string_as_T<bool>(const std::string& s)
{
	// Convert from a string to a bool
	// Interpret "false", "F", "no", "n", "0" as false
	// Interpret "true", "T", "yes", "y", "1", "-1", or anything else as true
	bool b = true;
	std::string sup = s;
	for (std::string::iterator p = sup.begin(); p != sup.end(); ++p)
		*p = toupper(*p);  // make string all caps
	if (sup == std::string("FALSE") || sup == std::string("F") ||
		sup == std::string("NO") || sup == std::string("N") ||
		sup == std::string("0") || sup == std::string("NONE"))
		b = false;
	return b;
}


template<class T>
T LanConfig::Read(const std::string& key) const
{
	// Read the value corresponding to key
	mapci p = m_Contents.find(key);
	if (p == m_Contents.end()) throw Key_not_found(key);
	return string_as_T<T>(p->second);
}


template<class T>
T LanConfig::Read(const std::string& key, const T& value) const
{
	// Return the value corresponding to key or given default value
	// if key is not found
	mapci p = m_Contents.find(key);
	if (p == m_Contents.end()) return value;
	return string_as_T<T>(p->second);
}


template<class T>
bool LanConfig::ReadInto(T& var, const std::string& key) const
{
	// Get the value corresponding to key and store in var
	// Return true if key is found
	// Otherwise leave var untouched
	mapci p = m_Contents.find(key);
	bool found = (p != m_Contents.end());
	if (found) var = string_as_T<T>(p->second);
	return found;
}


template<class T>
bool LanConfig::ReadInto(T& var, const std::string& key, const T& value) const
{
	// Get the value corresponding to key and store in var
	// Return true if key is found
	// Otherwise set var to given default
	mapci p = m_Contents.find(key);
	bool found = (p != m_Contents.end());
	if (found)
		var = string_as_T<T>(p->second);
	else
		var = value;
	return found;
}


template<class T>
void LanConfig::Add(const std::string& in_key, const T& value)
{
	// Add a key with given value
	std::string v = T_as_string(value);
	std::string key = in_key;
	Trim(key);
	Trim(v);
	m_Contents[key] = v;
	return;
}

}
